In a piano, the steel strings that are struck to produce music need to be held at relatively high tension. Because of that, the strings must be mounted to an apparatus that has high strength and structural integrity. Traditionally, this is accomplished by mounting the strings to a cast-iron plate (sometimes also referred to as a cast-iron frame, though this is technically incorrect as the frame properly refers to the wooden frame of the piano to which the plate mounts), which provides the strength and support necessary to maintain the tension required to hold the strings at their appropriate tuning. These cast-iron plates are typically manufactured in a factory through the multi-step and time-consuming process of pouring molten metal into a cast, cooling over a period of time, sand blasting for smoothing, and then painting, thus making the production of cast-iron plates time consuming and labor intensive. At standard tuning, the plate typically withstands 20 to 30 tons of string tension. This cast-iron plate contributes to over 50% of the instrument's weight.
Because of the relatively large size and weight of pianos, it would be desirable to produce piano parts that are lighter, thereby making the piano easier to move around. However, because of the structural requirements of the plate, producing suitable plates from a lighter material has heretofore been impossible without significantly sacrificing quality.
Thus, there is a need for improved piano components, such as the plate, that provide adequate structural integrity or strength, or even improved structural integrity or strength, while simultaneously reducing the weight and or size of the components or the resulting piano.